Custom Logger Plug-in

The preferred way to install a custom logger into a communicator is by setting the logger field of the communicator's IntializationData.

However, in some situations, you have no access to InitalizationData, for example:

you are writing an IceBox service
you want to install a custom logger without changing any source code

The plug-in facility allows you to inject your custom logger into the communicator at runtime, during communicator initialization.

Installing a Custom Logger

Ice provides a C++ plug-in class, Ice::LoggerPlugin, that installs a logger into the communicator in its constructor:

CPP

namespace Ice
{
    class LoggerPlugin : public Plugin
    {
    public:
          LoggerPlugin(const CommunicatorPtr& communicator, 
                       const LoggerPtr& logger);
        
          void initialize() override;
          void destroy() override;
    };
}

The implementation of initialize and destroy in LoggerPlugin are no-op.

Now, assuming you wrote a CustomLogger class that implements Ice::Logger, you can easily create a plug-in factory function that creates a LoggerPlugin and installs your logger into the communicator:

CPP

extern "C" Ice::Plugin* createCustomLoggerPlugin(
    const Ice::CommunicatorPtr& communicator,
    const std::string&,
    const Ice::StringSeq&)
{
    return new Ice::LoggerPlugin(communicator, make_shared<CustomLogger>());
}

Then, package your CustomLogger implementation and createCustomLoggerPluginin a shared library or DLL, and configure your communicator to load it at runtime. For example:

CODE

Ice.Plugin.CustomLogger=customlogger,0:createCustomLoggerPlugin

Even though you didn’t implement the plug-in class (Ice::LoggerPlugin), you are in effect creating a new plug-in since you choose the logger given to the LoggerPlugin constructor. As a result, you can pick any name for the plug-in factory function and the plug-in itself.

Installing a Custom Logger

See Also